A point to ponder about out and back rides:
I have used the "Velocity Predictor" to figure out whether round trip times are different between low and high wind rides, theoretically they are the same. However, I feel it is easier to maintain a particular speed in still conditions over a particular out and back course, than having a howling wind to deal with.
The only thing I can think of is that a cross wind can impact speed in both directions? Or perhaps it is much more difficult to manage the energy reserves in high winds (ie run empty too early or come home with the tank full).
Hell is riding home into the Perth south wester